Ingot-heating furnace



Dec. 10 1929; v NEUHAUS 13,738,84E

INGOT HEATING FURNACE Filed May 9. 1928 M van far:

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Watented Bee. l3, i929 nnunaus, or ennrwrrz, ennm'anv,

uirnnanv application filed May 9, 1928, Serial Ito.

@n rolling or other working metals, the ingots are generally heated in an elongated furnace through which they are pushed from, one end to the other. The heat is supplied to the principal heating zone which is situated at the delivery end of the furnace. The extension of the heating zone is limited, and the rate at which the rolling takes place with modern machinery, (usually one ingot a min ute) does not allow the ingots to stay any length oi time in the principal heating zone. The intensity ot the heat supplied to this zone is therefore considerable; but although the ingots may, on leaving the furnace, be in a state oi: white heat, it is'iound that they rapidly cool down in the rolling mill to a dull red. This is evidently due to the shortness of the time during which the ingots are exposed to the intense heat which only penetrates the outer portion of the ingot, the core being still comparatively cool.

The object ot the present invention is to remedy this defect, and the invention consists in the provision of a furnace having,

" beyond the principal heating zone, a heatequalizing zone wherein the ingots are retained after leaving said principal zone so as to allow the heat to penetrate to the core, the ingots being meanwhile exposed in said heat-equalizing zone to a lower temperature.

l oi? the acompanying drawings represents a, vertical longitudinal section of a turnace according to the invention, and

Fig. 2, a horizontal section of the same. The elongated turnace structure has a hearth which extends from end to end. The principal heating zone a occupies an intermediate portion of the structure and receives the heat from combustion chambers 7 and 7 arranged at opposite sides of the hearth.

At one side of the principal heating zone there is a pro-heating zone 2" which occupies one end portion of the structure. At the other side there is a heat-equalizing zone It which occupies the other end portion of the structure. The ingots b are introduced into the preheating zone at the end of the struc-- ture and pushed in known manner along guide rails g, 9 through the different zones in succession. There is a lateral outlet at in inner-traumas summon cream, and iii Germany Ma an, real.

the heat-equalizing zone through which the ingots are withdrawn 'trom the furnace for rolling or other treatment. The hot gases ASSIGNOR: T0 ADULT? KRAH, 013 blLEIWITfi,

from the principal heating zone are diverted over the hearth in both directions. Those gases which pass through the preheating zone above the hearth and the ingots are discharged through flues 70 which are fitted with dampers 3 The gases going in the opposite direction are led to the under side of the hearth, partly direct through a due a in the hearth near the combustion chambers, thus without loss of heat, and partly through a due if at the extreme end of the heat equalizing zone alter having passed over and transmitted heat to the latter. These gases pass under the entire hearth and row of ingots to a discharge flue k which is fitted with a damper 3 By adjusting the dampers e and s and by suitably dimensioning the dues l and a the flow ot gas can be regulated so that more or less will be led through the equalizing zone according to requirements.

By the provision of an equalizing zone as described, the ingots will have time to get uniformly heated throughout, and they will therefore be better able to retain their heat during the rolling, even it the unitorm tem perature should. be less than the surtace temperature at which the ingots are removed from furnaces 0t lrnown type.

The actual construction of the furnace structure may be varied within the scope ol the invention which is applicable to recuperative as Well as regenerative furnaces. linstead of arranging the combustion chambers and f at the sides out the hearth, they may e arranged above or below it, the paths p'ur sued by the gases being varied accordingly.

I claim:

An ingot heating iurnace comprising an elongated furnace structure having at one end a preheating zone, at the other end a till heat-equalizing zone, and between the two a means for discharging the gases at the end of the preheating zone.

KARL NEUHAUS. 

